De-fogging devices for removing moisture from mirrors are well known. The devices are commonly found in rooms where the humidity and/or temperature are above normal levels such as bathrooms, commercial laundries, steam baths, and saunas. Some de-fogging devices heat the mirrors by heating elements attached to their rear walls and require electrical junction boxes behind the mirrors to function. The junction boxes and wires to the boxes must usually be installed by licensed electricians. The junction boxes restrict the location of the mirrors and once the boxes are installed, they are permanently located and cannot be removed or relocated without significant cost. An added disadvantage of heating mirrors by this means is that the areas of the mirrors which are electrically heated are usually quite small and accordingly only relatively small areas of mirrors are cleared by the de-fogging devices.
Other de-fogging devices have heaters and fans for causing heated air to flow over mirrors but such devices are expensive to manufacture and are usually noisy and vibrate excessively because of their moving parts.